The present invention describes a novel, and general method to prepare 5-pyrimidinyl substituted imidazoles. Previous syntheses of this class of molecules utilized the van Leusen reaction (van Leusen, A. M., et. al. J. Org. Chem. 1977, 42, 1153), which involves the cycloaddition of an imine and a tosylisonitrile. Difficulties in preparing the aldehyde precursors to the desired imines limited the scope of this approach. In Adams et al., WO 95/02591 an improvement on the cycloaddition reaction is shown for similar compounds. However addition of a pyrimidine ring in an environmentally favourable and commercially feasible manner is still needed. The present invention employs a novel method of cycloaddition of a tosylisonitrile with an .alpha.-ketoaldimine to produce a 5-keto imidazole derivative. The 5-keto group serves as an excellent precursor for addition of the optionally substituted pyrimidine ring.